Gallstone formation is frequently accompanied by inflammation of the g
allbladder mucosa. Some gallstone components such as cholesterol, calc
ium bilirubinate, and calcium hydroxy apatite have been previously sho
wn to activate neutrophils. We investigated the effect on neutrophils
of the calcium carbonate polymorphs aragonite, calcite, and vaterite (
all found in gallstones). By chemiluminescence, superoxide, and degran
ulation assay, all three crystals were shown to cause rapid activation
of neutrophils. The potency of the crystals was aragonite > vaterite
> calcite. In vivo, crystals may be plasma-protein-coated before they
encounter neutrophils; therefore some experiments were repeated using
crystals that had been preincubated with plasma. For aragonite and vat
erite, protein adsorption decreased the chemiluminescence response by
approximately 50%. In contrast, protein-coated calcite crystals elicit
ed a greater chemiluminescence response than did uncoated crystals. In
summary, the calcium carbonate polymorphs are potent activators of ne
utrophils and thus have the potential to contribute to gallstone-assoc
iated cholecystitis.